https://wiki.ubuntu.com/MountWindowsSharesPermanently
sudo apt-get install cifs-utils
gedit ~/.smbcredentials
Enter your Windows username and password in the file:
username=msusername
password=mspassword
Save the file, exit the editor.
Change the permissions of the file to prevent unwanted access to your credentials:
chmod 600 ~/.smbcredentials
Then edit your /etc/fstab file (with root privileges) to add this line (replacing the insecure line in the example above, if you added it):
//servername/sharename /media/windowsshare cifs credentials=/home/ubuntuusername/.smbcredentials,iocharset=utf8,sec=ntlm 0 0
Save the file, exit the editor.
Finally, test the fstab entry by issuing:
sudo mount -a